n.
The period of time required for the earth to make one complete revolution around the sun, measured from one vernal equinox to the next and equal to 365 days, 5 hours, 48 minutes, 45.51 seconds. Also called astronomical year, tropical year.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.